{
  "url": "https://openlegislation.uk/air-quality-standards-wales-regulations-2007/schedule-1/part-2",
  "json_url": "https://openlegislation.uk/air-quality-standards-wales-regulations-2007/schedule-1/part-2.json",
  "legislation": "wsi/2007/717",
  "legislation_title": "The Air Quality Standards (Wales) Regulations 2007",
  "legislation_url": "https://openlegislation.uk/air-quality-standards-wales-regulations-2007",
  "path": "schedule/1/part/2",
  "kind": "part",
  "number": "2",
  "heading": "Margins of tolerance for benzene and nitrogen dioxide",
  "text": "Start of period during which the margin applies\nEnd of period during which the margin applies\nBenzene\nNitrogen dioxide (hourly limit value for the protection of human health)\nNitrogen dioxide (annual limit value for the protection of human health)\nComing into force of these Regulations\n31 December 2007\n3 μg/m3\n30 μg/m3\n6 μg/m3\n1 January 2008\n31 December 2008\n2 μg/m3\n20 μg/m3\n4 μg/m3\n1 January 2009\n31 December 2009\n1 μg/m3\n10 μg/m3\n2 μg/m3",
  "extent": null,
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/wsi/2007/717/schedule/1/part/2",
    "retrieved_at": "2026-10-29T00:01:33.213395+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}